Math question need help

Question

F(x)=3

what’s the domain? Can someone please explain well what’s the answer? I’m confused on all real numbers.

Answer 1

The domain is all real number

First, you have to understand what is "domain"

The domain is a set of all possible number

When you draw the graph of f(x) = 3, you will see a continuous horizontal line, which indicate every real value of x has an image, thus the domain is all real numbers

Answer 2

Generally f(x) is a function, in this case f(x) = 3. a function maps input to output.

let's imagine a different function for a moment: g(x) = x^2

For g(x), x is the input and g(x) is the output, so when x = 1, g(x) = 1^2 = 1

when x = -3, g(x) = (-3)^2 = 9

when x = infinity, g(x) = infinity^2 = +infinity

when x = -infinity, g(x) = (-infinity)^2 = +infinity

All that in mind, every function has two features: a DOMAIN and a RANGE (words can vary from textbook to textbook)

the DOMAIN is the possible values of the INPUT x

the RANGE is the possible values of the OUTPUT f(x) or g(x)

SO, for g(x) = x^2, the DOMAIN is all real numbers, while the RANGE is only the positive real numbers (and 0)

What is a real number? A real number is basically any number. It can be a whole number or a decimal, it can be positive, negative, or zero, it can have a fractional representation (3/4) or it can NOT, like pi, which cannot be reduced to a fraction.

So when you read real number, for our purposes, just think "any number"

Now, with all that, the function F(x) = 3.

The DOMAIN is any value that x can take. This is a strange case because F(x) is NOT DEPENDENT on x. Whatever value x has, F(x) will ALWAYS be 3.

So x can basically do whatever it wants, which we can say more formally as:

x can take on the value of any real number

or, put another way

the domain of F(x) is all real numbers

Please feel free to reply or reach out if you have any more questions!